A004283 Least positive multiple of n written in base 3 using only 0 and 1.

1, 11, 10, 11, 101, 110, 1001, 1111, 100, 101, 11111, 110, 111, 1001, 1010, 11011, 10011, 1100, 100011, 1111, 10010, 111001, 100101, 11110, 110001, 111111, 1000, 1001, 1011011, 1010, 1011, 100111, 111110, 1011111, 101101, 1100, 1101

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A005836.

Programs

Maple

h:= proc(n)
  option remember;
  local t,x;
  t:= n mod 3;
  if t = 2 then -1
  else
    x:= procname((n-t)/3);
    if x = -1 then -1
    else 10*x + t
    fi
  fi
end proc:
h(0):= 0:
h(1):= 1:
A004283:= proc(n) local k,r;
  for k from 1 do
    r:= h(k*n);
    if r <> -1 then return r fi
  od
end proc:
seq(A004283(n),n=1..100); # Robert Israel, Dec 26 2015

Mathematica

lpm3[n_]:=Module[{k=1},While[DigitCount[k*n,3,2]>0,k++];FromDigits[ IntegerDigits[ k*n,3]]]; Array[lpm3,40] (* Harvey P. Dale, Mar 02 2020 *)

PARI

a(n) = {k=1; while (vecmax(digits(k*n, 3)) != 1, k++); subst(Pol(digits(k*n, 3)), x, 10);} \\ Michel Marcus, Dec 27 2015

Extensions

a(34) corrected by Sean A. Irvine, Dec 26 2015